HEAVY DUTY PNEUMATIC TIRE

摘要

A heavy duty pneumatic tire includes a tread portion provided with a zigzag central main groove having zigzag pitches of from 40 to 50. The central main groove includes a bottom and a pair of groove walls. Each groove wall includes a bottom side steep sloped portion and a top side gentle sloped portion. The steep sloped portion includes a height of from 10% to 35% of a depth of the central main groove and an angle of from 0 to 10 degrees with respect to a tire normal line of a tread ground-contact surface. The gentle sloped portion extends radially outwardly from the steep sloped portion. Each groove wall includes an internal corner protruding and an external corner, and the angle of the gentle sloped portion decreases in a range of from 15 to 25 degrees from the internal corner toward the external corner.

主权项

1. A heavy duty pneumatic tire comprising:
a tread portion comprising a central region having a 10% width of a tread width centered on a tire equator, the central region being provided with at least one circumferentially and continuously extending zigzag central main groove having zigzag pitches of from 40 to 50; the at least one central main groove comprising a bottom and a pair of groove walls; each groove wall comprising a bottom side steep sloped portion and a top side gentle sloped portion; the steep sloped portion comprising a height of from 10% to 35% of a groove depth of the central main groove from the bottom and an angle of from 0 to 10 degrees with respect to a tire normal line of a tread ground-contact surface; the gentle sloped portion extending from the steep sloped portion toward the tread ground-contact surface with an angle greater than that of the steep sloped portion; the central main groove having a groove width of from 4.0 to 12.0 mm between the steep sloped portions; and each groove wall comprising an internal corner protruding toward a groove centerline of the central main groove and an external corner protruding an opposite direction to the center line, the angle of the gentle sloped portion decreasing in a range of from 15 to 25 degrees from the internal corner toward the external corner.